A conductive polymer is used in an electrode or the like of a back-up battery of an electrolytic capacitor or an electronic appliance or a lithium ion battery used in a mobile phone or a lap-top PC.
In addition to its electric characteristics, polyaniline, that is one of conductive polymers, has merits and characteristics that it can be synthesized relatively easily from inexpensive aniline and exhibits excellent stability for oxygen or the like in the conductive state. By a method disclosed in Patent Document 1, for example, a polyaniline solution can be obtained easily. Due to its solution state, polyaniline can be used in many applications.
According to applications, a polar solvent is required, not a non-polar solvent. In the case of polyaniline, it is possible to obtain not only a solution of a non-polar solvent but also a solution of a polar solvent (see Patent Document 2, for example).